Tales of a MD/PhD student

Wednesday, May 25, 2005

Economics and Psychology

Economics - to the great dismay of economists - is merely a branch of psychology. It deals with individual behaviour and with mass behaviour. Many of its practitioners sought to disguise its nature as a social science by applying complex mathematics where common sense and direct experimentation would have yielded far better results.

The outcome has been an embarrassing divorce between economic theory and its subjects.

The article outlines many of the difficulties in economics research, and why economics should not necessarily be considered a science.

Scientific theories must also pass the crucial hurdles of testability, verifiability, refutability, falsifiability, and repeatability. Yet, many economists go as far as to argue that no experiments can be designed to test the statements of economic theories.

It is difficult - perhaps impossible - to test hypotheses in economics for four reasons.

Ethical - Experiments would have to involve human subjects, ignorant of the reasons for the experiments and their aims. Sometimes even the very existence of an experiment will have to remain a secret (as with double blind experiments). Some experiments may involve unpleasant experiences. This is ethically unacceptable.

Design Problems - The design of experiments in economics is awkward and difficult. Mistakes are often inevitable, however careful and meticulous the designer of the experiment is.

The Psychological Uncertainty Principle - The current mental state of a human subject can be (theoretically) fully known. But the passage of time and, sometimes, the experiment itself, influence the subject and alter his or her mental state - a problem known in economic literature as "time inconsistencies". The very processes of measurement and observation influence the subject and change it.

Uniqueness - Experiments in economics, therefore, tend to be unique. They cannot be repeated even when the SAME subjects are involved, simply because no human subject remains the same for long. Repeating the experiments with other subjects casts in doubt the scientific value of the results.

The undergeneration of testable hypotheses - Economic theories do not generate a sufficient number of hypotheses, which can be subjected to scientific testing. This has to do with the fabulous (i.e., storytelling) nature of the discipline. In a way, economics has an affinity with some private languages. It is a form of art and, as such, it is self-sufficient and self-contained. If certain structural, internal constraints and requirements are met - a statement in economics is deemed to be true even if it does not satisfy external (scientific) requirements. Thus, the standard theory of utility is considered valid in economics despite overwhelming empirical evidence to the contrary - simply because it is aesthetic and mathematically convenient.

Hmm...definitely some interesting considerations that are worth further thought and study...

Wednesday, May 18, 2005

Neuroeconomics

Given my interest in all things relating to neuroimaging, and the positive reception I got from What's the deal with Neuromarketing? I thought I'd bring up a related field of study: Neuroeconomics.

A recent article in Technology Review entitled The Economics of Brains underscores the implications of fMRI research as it relates to economic theory. The hope is that by understanding how the brain works in things like decision making and reward processing, economists will be able to better modify their theories to account for "irrational" behavior. Of course, the question is, considering the level of neuroeconomic research occurring today, should economists really care?

Perhaps understanding how the brain works is more trouble than it’s worth. After all, some recent findings are not at first glance very economically enlightening. Anyone who has regretted an impulse purchase, for instance, would be unsurprised to learn that evaluations of immediate and delayed rewards use different parts of the brain. For now, neuroeconomics is subject to the criticisms that plague psychology: that its experiments show what is already intuitively obvious, and its models are descriptive, not quantitative. But Stanford psychologist Brian Knutson and psychiatrist Richard Peterson are trying to answer that criticism. Their paper in a forthcoming issue of Games and Economic Behavior reports that subjects seem to use different parts of their brains when they consider financial gains and when they consider financial losses; more recently, they have found that subjects use different parts again to evaluate the magnitude and probability of those gains and losses. Knutson and Peterson’s work is part of an increasing effort to figure out how economic utility may be coded quantitatively in various regions of the brain. If economists could track the different components of utility in a statistical way, they could understand why some people take risks and some don’t—and possibly predict their future behavior.

Obviously, like most neuroimaging research, the subfield of neuroeconomics is still quite young, and only time will tell how effective this type of research will be in shaping economic theory. One interesting aspect of this field is that by putting the results in an economic framework (as opposed to a marketing framework), researchers have been able to isolate themselves from criticisms such as those directed at neuromarketing researchers (see What's the deal with Neuromarketing?). On the surface, both fields study very similar concepts, but neuroeconomic research seems to encompass a wider variety of issues.

For those of you more interested in the topic, I refer you to the following sites:

The Ethical Brain

The New York Times recently published an interview with Dr Gazzaniga, a prominent neuroscientist, who has just published a new book entitled The Ethical Brain.

I found the following comments particularly interesting:

In "The Ethical Brain," Dr. Gazzaniga discusses his views on stem cell research, along with a range of other important issues. He describes his worry that the techniques of neuroscience may be misused.

For example, he thinks it is wrong to use neuroimaging as a lie detector or as a tool to determine whether criminals are responsible for their crimes. "It shouldn't be dragged into the courtroom," he said. "I think it's totally misused if you're trying to find the errant pixel in the brain that's responsible for why someone killed someone."

Neuroscience's biggest contribution to ethics, Dr. Gazzaniga predicted, is only just emerging: a biological explanation of morality. "In the next 20 years, we're probably going to define why our species seems to have a certain sort of moral compass," he said.

Current research suggests that this moral compass appears to be the product of the human brain's intricate circuitry for understanding other people's thoughts and feelings. Just looking at pictures of people stubbing their toes in doors, for example, activates the same regions of the brain that switch on when people stub their own toes. "When I have an empathetically moment, I literally feel your pain," Dr. Gazzaniga said.

Dr. Gazzaniga argues that when we experience these feelings, the brain's interpreter produces rational explanations for them. The particular explanation it produces depends on a person's particular upbringing. "Each culture may build up a theory, and that may be passed down as traditions and religious moral systems."

But, he said, "the basic reason you don't kill is because your brain tells you it's not a good idea to kill."

Will we ever be able to "define our moral compass" using techniques such as neuroimaging? I'm not sure. Afterall, it stands to reason that other species have a similar "moral compass," but though imaging animals occurs all the time, it would be much harder to study. Perhaps neuroimaging will provide some scientific support for philosophical theories regarding innate morality and ethics, but I'm not sure that the theories can ever be proven. Afterall, if morality can be defined in the brain by a single voxel, what does that really tell us in the broader sense? That knowing that it is wrong to kill comes down to a single group of neurons? Is that group of neurons enough to "prove" that we have a deeper sense of morality than a dolphin (afterall, putting dolphins in a scanner may prove rather difficult)?

One thing's for sure though....Dr. Gazzaniga's book is on my reading list this summer. Science may never be able to prove these philisophical theories, but it is fun to think about!

"In the current issue of Nature Neuroscience, however, Frank Tong, a cognitive neuroscientist at Vanderbilt University, and Yukiyasu Kamitani, a researcher in Japan, announced that they had discovered a way of tweaking the brain-scanning technique to get a richer picture of the brain's activity. Now it is possible to infer what tiny groups of neurons are up to, not just larger areas of the brain. The implications are a little astonishing. Using the scanner, Tong could tell which of two visual patterns his subjects were focusing on -- in effect, reading their minds. In an experiment carried out by another research team, the scanner detected visual information in the brains of subjects even though, owing to a trick of the experiment, they themselves were not aware of what they had seen."

Is being able to tell what picture someone is looking at really "reading their minds?" Although some fear that fMRI will be the next pre-employment screening (like drug screening is today), with its ability to uncover racism and other potentially undesirable personality traits, will it ever really pan out in the future? Why aren't we drawing everyone's blood to test for high blood pressure, high cholesterol, diabetes, etc. to see if they will be a burden on company insurance plans? I have heard the argument that fMRI will soon be used to replace pen and paper tests of personality used in certain employment areas. Afterall, you can't "lie" in the scanner. But fMRI is expensive, complicated to interpret, and isn't ready for individual level analysis in most cases. So, is fMRI really a potential invasion of our privacy? Well, if you're concerned that someone can tell what picture that you are looking at (without looking at your eyes), maybe. But if your concern is at a broader level, sit back, because we wont be anywhere near that point for awhile.

And finally, The Center for Cognitive Liberty which raises some interesting questions, such as the possible issues related to successful memory enhancement. "What if emergency room personnel automatically begin giving memory-diminishing drugs to trauma victims? What if you are the victim of a violent crime and want to forget what happened to you, but need those memories in order to testify or identify the perpetrator? What if you are the only eye-witness to a crime, could the government compel you to take a memory-boosting drug at least until you testify in court?" While I believe many of these potential issues are just as far fetched as those brought up on the Commercial Alert neuromarketing site, it is some food for thought...

Why wont you put your helmet on?

This afternoon, one of my new neighbors was teaching her daughter to ride her bike. Her other daughter was on a bike as well. None of the three were wearing helmets.

According to research conducted by the National SAFE KIDS Campaign, nearly half of severe injuries from bike accidents are traumatic brain injuries. And though young adults generally have a better outcome from TBI than older adults, younger children (such as my kindergarten-aged neighbor) are particularly vulnerable to brain injury (especially frontal injury) because many higher level cognitive functions haven't fully developed.

I wanted to tell the kids to put on a helmet. If their Mom wasn't riding with them (sans helmet), I may have suggested that they go and get them when I was out getting my mail. But I didn't, partially because I don't know them, and I feel weird about telling other people's kids what they should do. I understand that it can be difficult to make older children wear helmets, but when you are teaching your child to ride a bike, how hard can it be? Around here, helmets can be purchased at local fire stations for $10 each, and are given away free at local hospitals.

Perhaps my outrage is colored by the fact that I've always worn a helmet, and all of my cousins are good about wearing theirs. I actually even had a cousin tell me the other day, "I can't ride bikes today because I left my helmet at home." Of course, such easy compliance didn't come without a price; a close family friend died tragically two years ago from a backwards fall when rollerblading with her son. The greatest tragedy of all was that just before pulling out of the driveway to go to the park, her husband called out to make sure she had remembered her helmet. After the funeral, he found it their garage. And when my older cousins and I were growing up, there was always my fictitious Uncle John, who hurt his head falling off his bike and was never quite the same (or maybe that was from falling over the railing, or tripping because his shoes weren't tied, or from getting sick because he didn't wash his hands before dinner....)

Moral of the story? Wear a helmet! Next time I go to the Children's Hospital, I'm going to pick up flyers for the helmet drives and put them in my neighbors' mailboxes. I'm sure that these kids, with their shiny new bikes, probably already have them, but hopefully a little information on the benefits of wearing a helmet will give them (and their parents) a push in the right direction.

Wednesday, May 04, 2005

Submissions for Grand Rounds 33

Azygos, the host for next week's Grand Rounds, has put out a call for submissions.

He writes, "I would like to suggest that next week submissions focus on some personal interaction, intervention or extra steps you took in the course of making a difference in a patients or patient’s families life. To often we here about the bad doctor, insensitive nurse, or the uncaring treatment one has received from a healthcare worker. We never hear about the extra hours put in by doctors, nurses, PA’s, and nurse practitioners to make sure the patient is appropriately cared for. We don’t hear about the classes all of us attend in the course of our practice just to try and stay on top of current therapy and treatment. Patients don’t hear about the five hours of phone calls the provider had to make to arrange a lifesaving treatment. Maybe some would disagree but I think pulling the veil back to reveal some of the intricacies of patient care might give pause to some before complaining about the care they received."

It's a great suggestion; I'd love to hear these kinds of stories as well!

Monday, May 02, 2005

Grand Rounds XXXII: A Day In The Life of a Medical Student

12:35 AM

Finish studying and do a final check of Medlogs. Stumble upon a post by The Anonymous Clerk asking Does NPO Include Holy Food? Decide to head to bed. Because tomorrow will be filled with interesting clinical correlation lectures instead of biochemistry, I'm actually planning on going to class in the morning....

6:45 AM

Radio alarm goes off. Hit snooze

6:52 AM

Hit Snooze again. Why are lectures always so early?

6:59 AM

Drag myself out of bed. On the radio, Red State Moron reports the latest on surrogacy and quintuplets. I wonder why medical stories are the only thing that can drag me out of bed in the morning. Hit the Shower.

7:15 AM

Grab breakfast while checking the traffic on Good Morning America. Diane Sawyer introduces Denni from The Break Down Manual who has an important message about postnatal depression. Though it may make me late, I decide to watch the whole segment.

7:45 AM

8:00 AM

Clinical Correlations Lecture: Dr. Rack, the Sleep Doctor finishes up his lectures on narcolepsy Looking out at my fellow students, I'm amused that a sleep lecture was scheduled so early in the morning. While Dr. Rack is anything but boring, our collective sleep deficit seems to have overcome certain students' interest in the topic at hand.

6:15 PM

As I head over to the research building, I run into Aggravated DocSurg who muses on the tragic consequences of a missed diagnosis, and how it hits close to home. I empathize; in high school, my mother attempted (but thankfully, did not complete) suicide three times, and everytime it happened, we were sure that she was finally out of danger.

6:30 PM

Journal Club: Orac describes the biomedical meeting creatures he encountered at the poster session during his last conference. I can relate to his experiences as it wasn't so long ago that I went to my first major conference and presented a poster in the very first session. Nervous, because I had never even been to a conference before, I stayed up half the night looking up obscure facts that someone might ask me about. It turns out that most of my poster audience simply wanted to be "walked through the poster." I wish I had been warned.... Once everyone has arrived, Dr. Andy presents a recent article about the possible risks (or lack thereof) of biotech foods.

Disclaimer

This is a personal web log which simply reflects the opinion and experiences of a single student. Unless otherwise cited, statements on this blog do not represent the opinions of anyone other than this author. Content on this blog does not in any way represent the opinions of my university, hospital, or fellow students. The information presented here is solely intended for discussion, and should not be taken as fact. I am merely a student, and am not a doctor. Imagine any other additions to this disclaimer as you see fit!